docs: def freeze(self):
          """Call this method if you want to make your response object ready for
          being pickled.  This buffers the generator if there is one.  It will
          also set the `Content-Length` header to the length of the body.
  
          .. versionchanged:: 0.6
             The `Content-Length` header is now set.
          """
          # we explicitly set the length to a list of the *encoded* response
          # iterator.  Even if the implicit sequence conversion is disabled.
          self.response = list(self.iter_encoded())
          self.headers['Content-Length'] = str(sum(map(len, self.response)))